Have you ever gotten sick just thinking about something? If so, you possibly have experienced the nocebo effect. The nocebo effect is the negative stepsister of the placebo effect, where we feel good after eating foods, taking a remedy, or doing something we believe is healthy.
With the nocebo effect, people can experience real and extraordinary physical and mental symptoms of illness, even paralysis, when they believe they've eaten or been exposed to something they think or fear could be harmful. The nocebo effect is behind most fears of unseen dangers lurking around us, especially in our food, and explains how people can sincerely believe that something is making them sick—even when there is no biological basis for their symptoms. When we're told, or know, there is no scientific basis for what we're experiencing, it's still hard to believe that our minds can be that powerful.
The term nobeco, which means “I will harm,” was introduced in the 1960s, and it is very real. Around 60 percent of patients undergoing chemotherapy start feeling sick before their treatment. The nocebo effect can also be catching. When we expect something to make us ill, we start looking for signs of illness, and studies have shown that if you hear of or observe a possible side effect, you are more likely to develop it yourself. (1)
Some Examples:
* Sweden is one of the countries at the forefront of restricting chemical use in Europe. It has a policy of making its environment 'toxic-free' and the country led in the preparation of the European Commission White Paper “Strategy For a Future Chemicals Policy.” Yet as Bill Durodie notes, “Sweden has one of the highest levels of self-reported sensitivities to chemicals in the developed world. It would appear then, that too much risk awareness can quite literally make you sick.” (2)
* In a study in the early 1980s, 34 college students were told an electric current would be passed through their head, and the researchers warned that the experience could cause a headache. Though not a single volt of current was used, more than two-thirds of the students reported headaches. (3)
* Drinking water fluoridation was first introduced in Grand Rapids, Michigan in 1945. Calls began coming in to city offices from people complaining of sore gums and peeling tooth enamel. One woman even claimed that all her teeth had fallen out. These calls arrived in early January, when some press reports had stated that fluoridation would begin, but some weeks before the actual advent of fluoridation on January 25. (4)
* Call it fear of spraying. In one study, researchers spewed distilled water from planes over residential neighborhoods without telling anyone what the spray contained. The intent was to gauge public phobia of chemicals. Sure enough, the experimenters were soon deluged with complaints of frightened folks who claimed the spray was causing cows to abort, dogs to shed and children to get sick.
* After the 1995 Aum Shinrikyo nerve-gas attack in Tokyo, hospitals were flooded with patients suffering form the highly publicized symptoms, like nausea and dizziness, but who had not in reality been exposed to the sarin. This is common in disasters where the agent is invisible, as with chemicals or radiation. (5)
* Electrosensitivity has been studied as it relates to people living near cell phone towers or hydro lines. A Paris household blamed three installed cell phone antennas in their area for causing headaches, nosebleeds and a metallic taste in the mouths of some residents. The one problem with this complaint—the antennas were never activated. (6)
* Some people devote their lives to avoiding Wi-Fi altogether. Sufferers of Wi-Fi syndrome say that the radio waves used in mobile communication cause headaches, nausea, exhaustion, tingling, trouble concentrating, and gastrointestinal distress, among other symptoms. As for the Wi-Fi syndrome, a recent analysis of forty-six studies involving nearly twelve hundred volunteers concluded that the signals do not cause the symptoms. “There is a considerable body of evidence that electromagnetic hypersensitivity might actually be the result of a so-called nocebo effect,” explained Dr. Michael Witthoft of Johannes Gutenburg University Mainz, whose recent study illustrates how media reports about health risks may trigger or amplify the nocebo effect in some people. (7)
Until recently, we knew very little about how the nocebo effect works. Now, however, besides Witthoft's work, a number of other scientists are beginning to make headway. (8)
A study in February 2011 led by Oxford's Professor Irene Tracey showed that when volunteers feel nocebo pain, corresponding brain activity is detectable in an MRI scanner. This shows that, at the neurological level at least, these volunteers really are responding to actual non-imaginary pain. (9)
Fabrizio Benedetti, of the University of Turin, and his colleagues have managed to determine one of the neurochemicals responsible for converting the expectation of pain into a genuine pain perception. The chemical is called cholekcystokinin and carries messages between nerve cells. When drugs are used to block cholekcystokinin from functioning, patients feel no nocebo pain, despite being just as anxious. (10)
Sandy Szwarc sums this up well. “We can become convinced that exposure to even a minuscule amount of a chemical or contaminant can harm our health, just as a minuscule amount of healing substance can heal—when neither can. The resulting symptoms can be extraordinary and far beyond anything we might ever imagine the power of suggestion could do to us. And when fears of a chemical threat or exposure are shared among a group of people, the symptoms can spread. We do not help people by spreading sensationalized and unsupportable scares or using the suffering of troubled souls as entertainment.” (11)
References
1. Helen Pilcher, “Beware with doctors,” New Scientist, 202, 30, May 16, 2009
2. Bill Durodie, “The true cost of precautionary chemicals regulation,” Risk Analysis, 23, 389, 2003
3. Brian Reid, “The nocebo effect: placebo's evil twin,” The Washington Post, April 30, 2002
4. R. Allan Freeze and Jay H. Lehr, The Fluoride Wars, (New York, John Wiley & Sons, 2009), 109
5. Gareth Cook, “The nocebo effect: how we worry ourselves sick,” newyorker.com, April 3, 2013
6. Tyler Hamilton, “Noise protestors howling about windfarms,” thestar.com, May 11, 2009
7. “The nocebo effect: media reports may trigger symptoms of a disease,” uni-maize.de/presse, May 6, 2013
8. Penny Sarchet, “The nocebo effect: Wellcome Trust science writing prize essay, guardian.co.uk, November 12, 2011
9. Ulrike Bingel et al.,” The effect of treatment expectation on drug efficacy: imaging the analgesic benefits of the opioid Remifentanil,” Science Translational Medicine, 3, 70ra14, February 2011
10. Fabrizio Benedetti, “The biochemical and neuroendocrine bases of the hyperalgesic nocebo effect,” Journal of Neuroscience, 26, 12014, November 15, 2006
11. Sandy Szwarc, “New Mexico is being irradiated by Wi-Fi?” junkfoodscience.blogspot.com, May 27, 2008
